[lld] [lld][WebAssembly] Allow `--no-stack-first` in addition to `--stack-first` (PR #166384)

[Kevin Gibbons via llvm-commits]

================
@@ -250,8 +250,9 @@ def no_entry: FF<"no-entry">,
 def no_shlib_sigcheck: FF<"no-shlib-sigcheck">,
   HelpText<"Do not check signatures of functions defined in shared libraries.">;
 
-def stack_first: FF<"stack-first">,
-  HelpText<"Place stack at start of linear memory rather than after data">;
+defm stack_first: B<"stack-first",
+    "Place stack at start of linear memory",
+    "Place the stack after static data refion (default)">;
----------------
bakkot wrote:

```suggestion
    "Place the stack after static data region (default)">;
```

https://github.com/llvm/llvm-project/pull/166384